With the world's focus on wearable electronics, the scientific community has anticipated the plasticine-like processability of electrolytes and electrodes. A bioinspired composite of polymer and phase-changing salt with the similar bonding structure to that of natural bones is a suitable electrolyte candidate. Here, Wang et al. reported a water-mediated composite electrolyte by simple thermal mixing of crystallohydrate and polymer. The processable phase-change composites have significantly high mechanical strength and high ionic mobility.